1. Field of the Invention
The present invention relates to a multilayer ceramic capacitor and a structure for mounting a circuit board of a multilayer ceramic capacitor.
2. Description of the Related Art
A multilayer ceramic capacitor, a laminated chip electronic component, is a chip-type condenser installed on a printed circuit board (PCB) of various electronic products such as imaging devices (or video display apparatuses) such as liquid crystal displays (LCDs), plasma display panels (PDPs), and the like, computers, smart phones, portable phones, and the like, serving to charge and discharge electricity.
A multilayer ceramic capacitor (MLCC), having advantages such as compactness, guaranteed high capacity, and ease of mountability, may be used as a component of various electronic devices.
The MLCC may include a plurality of dielectric layers and internal electrodes, having a structure in which internal electrodes having different polarities are alternately laminated between the dielectric layers.
The dielectric layers have piezoelectric and electrostrictive properties. Thus, when a direct current (DC) or alternating current (AC) voltage is applied to an MLCC, a piezoelectric phenomenon occurs between internal electrodes, generating vibrations.
Vibrations may be transferred to a PCB on which the MLCC is mounted, through solders of the MLCC, inducing the entirety of the PCB to become an acoustic surface radiating vibrating sound as noise.
Vibrating sound may correspond to audio frequencies ranging from 20 Hz to 2000 Hz, making users uncomfortable, and such a vibrating sound causing discomfort for users is known as acoustic noise.
In order to reduce acoustic noise, a product in which a thickness of a lower cover layer of an MLCC is increased has been studied.
Also, an MLCC having an increased thickness lower cover layer is mounted as a horizontal mounting type MLCC such that the thick lower cover layer is positioned at the bottom thereof on a printed circuit board (PCB) to advantageously reduce acoustic noise.
Meanwhile, research into reducing acoustic noise in the case that the MLCC having the increased thickness lower cover layer is mounted on a PCB is further required.